Recent prefix assignments

5 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, last 30 days — NPA 951

ONVOY, LLC - CA 5

New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025

Recent NPA-NXX prefix assignments
Assigned	NPA-NXX	Thousands-blocks taken (last-4 opening)	Code holder	OCN	Rate center	State
—	951-415	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	CORONA	CA
—	951-426	0–9 XXXall 10 · 4 holders which blocks →	T-MOBILE USA, INC.	6529	HEMT SNJC	CA
—	951-431	not yet reported which blocks →	PACIFIC BELL	9740	COLTON	CA
—	951-436	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks →	T-MOBILE USA, INC.	6529	PERRIS	CA
—	951-440	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	MURRIETA	CA
—	951-442	0–9 XXXall 10 · 3 holders which blocks →	T-MOBILE USA, INC.	6529	PERRIS	CA
—	951-443	5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	FRONTIER CALIFORNIA INC.	2319	PERRIS	CA
—	951-444	0–9 XXXall 10 · 4 holders which blocks →	BANDWIDTH.COM CLEC, LLC - CA	981E	CORONA	CA
—	951-453	none assigned yet which blocks →	T-MOBILE USA, INC.	6529	RIVERSIDE	CA
—	951-461	4XXX5XXX7XXX8XXX · 2 holders which blocks →	FRONTIER CALIFORNIA INC.	2319	MURRIETA	CA
—	951-465	0–9 XXXall 10 · 4 holders which blocks →	BANDWIDTH.COM CLEC, LLC - CA	981E	RIVERSIDE	CA
—	951-471	6XXX7XXX9XXX · 3 holders which blocks →	FRONTIER CALIFORNIA INC.	2319	ELSINORE	CA
—	951-473	0–9 XXXall 10 · 5 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	MURRIETA	CA
—	951-479	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	CORONA	CA
—	951-485	not yet reported which blocks →	FRONTIER CALIFORNIA INC.	2319	MORENO	CA
—	951-486	1XXX8XXX which blocks →	FRONTIER CALIFORNIA INC.	2319	MORENO	CA
—	951-487	3XXX4XXX5XXX · 3 holders which blocks →	FRONTIER CALIFORNIA INC.	2319	HEMT SNJC	CA
—	951-488	2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks →	FRONTIER CALIFORNIA INC.	2319	MORENO	CA
—	951-490	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	FRONTIER CALIFORNIA INC.	2319	PERRIS	CA
—	951-491	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks →	FRONTIER CALIFORNIA INC.	2319	TEMECULA	CA
—	951-492	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	FRONTIER CALIFORNIA INC.	2319	HEMT HEMT	CA
—	951-493	3XXX6XXX7XXX8XXX · 3 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - CA	7139	CORONA	CA
—	951-501	4XXX6XXX9XXX · 2 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	TEMECULA	CA
—	951-504	not yet reported which blocks →	AMERICAN MESSAGING SERVICES, LLC	9748	RIVERSIDE	CA
—	951-505	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	RIVERSIDE	CA
—	951-506	not yet reported which blocks →	FRONTIER CALIFORNIA INC.	2319	TEMECULA	CA
—	951-509	not yet reported which blocks →	PACIFIC BELL	9740	ARLINGTON	CA
—	951-511	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	CA
—	951-515	none assigned yet which blocks →	T-MOBILE USA, INC.	6529	CORONA	CA
—	951-520	3XXX5XXX6XXX7XXX · 2 holders which blocks →	PACIFIC BELL	9740	CORONA	CA
—	951-522	not yet reported which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	RIVERSIDE	CA
—	951-527	0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - CA	8826	IDYLLWILD	CA
—	951-529	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	RIVERSIDE	CA
—	951-530	0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS	671J	RIVERSIDE	CA
—	951-531	0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS	671J	CORONA	CA
—	951-532	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	CORONA	CA
—	951-533	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	RIVERSIDE	CA
—	951-536	none assigned yet which blocks →	T-MOBILE USA, INC.	6529	RIVERSIDE	CA
—	951-537	0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	LEVEL 3 TELECOM OF CALIFORNIA, LP - CA	7718	HEMT HEMT	CA
—	951-538	none assigned yet which blocks →	T-MOBILE USA, INC.	6529	RIVERSIDE	CA
—	951-540	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - CA	649C	LAKEVIEWNU	CA
—	951-541	1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - CA	8826	TEMECULA	CA
—	951-543	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - CA	8826	RIVERSIDE	CA
—	951-544	none assigned yet which blocks →	T-MOBILE USA, INC.	6529	RIVERSIDE	CA
—	951-549	not yet reported which blocks →	PACIFIC BELL	9740	CORONA	CA
—	951-550	1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks →	T-MOBILE USA, INC.	6529	PERRIS	CA
—	951-552	0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - CA	8826	ARLINGTON	CA
—	951-555	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	DIR ASST	CA
—	951-556	0–9 XXXall 10 · 5 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	ARLINGTON	CA
—	951-561	0–9 XXXall 10 · 3 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA	6006	TEMSCL CNY	CA

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.